Problem with JHD 162A LCD - Electronic Circuits Projects Diagrams Free

mhkhosravi · 30th May 2006, 03:03 PM

Hello

I have made a simple circuit with Atmega16 that writes only a word on LCD.
when I connect all parts, the LCD only shows full boxes in the second line and the first line is empty.
the LCD shows this even when the micro is off !!!
The program is correct.
the connections is correct too.
I used another LCD and micro but they did the same.
I dont know where is the problem?!

please help me about this ....

**Nigel Goodwin** · 30th May 2006, 03:24 PM

If the contrast is turned up too high, and the LCD isn't initialised at all, then you get the single line of blocks on the display - this is normal, and shows the LCD is worked to some extent at least.

As it doesn't work how do you know the program and connections are correct?, one (or both) of then are obviously NOT OK.

mhkhosravi · 30th May 2006, 03:39 PM

because the program is simple, in BASCOM I wrote :

$regfile = "M16def.dat"
$crystal = 8000000
Config Lcdpin = Pin , Db4 = Pinc.4 , Db5 = Pinc.5 , Db6 = Pinc.6 , Db7 = Pinc.7
_ , E = Pinc.3 , Rs = Pinc.2
Config Lcd = 16 * 2
Lcd "HELLO"

and the connections are this way :
pins :
1,3,5 -> ground
2 -> VCC
6 -> Pinc.3
etc ...

I saw this configuration in some mannuals, but it does not work.
If the problem was about the contrast, then only 5 characters must be filled , or all 32 charsets, but only 16 characters of second line become black boxes

**Nigel Goodwin** · 30th May 2006, 04:05 PM

Quote:

Originally Posted by mhkhosravi

because the program is simple, in BASCOM I wrote :

$regfile = "M16def.dat"
$crystal = 8000000
Config Lcdpin = Pin , Db4 = Pinc.4 , Db5 = Pinc.5 , Db6 = Pinc.6 , Db7 = Pinc.7
_ , E = Pinc.3 , Rs = Pinc.2
Config Lcd = 16 * 2
Lcd "HELLO"

and the connections are this way :
pins :
1,3,5 -> ground
2 -> VCC
6 -> Pinc.3
etc ...

I saw this configuration in some mannuals, but it does not work.
If the problem was about the contrast, then only 5 characters must be filled , or all 32 charsets, but only 16 characters of second line become black boxes

I repeat, how do you know the program is correct? - that above doesn't mean much!, I've no idea what it might create - have you?.

If it doesn't work then something is wrong, either it's connected wrong, or the program is wrong (or both) - if they are both correct then it will work!.

mhkhosravi · 30th May 2006, 04:48 PM

ok! it may be from program or connections.
but which and where?

**Nigel Goodwin** · 30th May 2006, 06:28 PM

Quote:

Originally Posted by mhkhosravi

ok! it may be from program or connections.
but which and where?

The only person who can determine that is YOU, we don't have your project ourselves.

I can point you to my tutorials, which give both a tested working layout, and tested working code - but it's in assembler.

akg · 31st May 2006, 08:02 AM

Quote:

Originally Posted by mhkhosravi

ok! it may be from program or connections.
but which and where?

in ur postes we don't see any lcd initialisation code or lcd connection pin details. without these it will be impossible to make an useful comment.

mhkhosravi · 31st May 2006, 06:02 PM

this is for LCD configuration (in BASIC language, with BASCOM ) :
Config Lcdpin = Pin , Db4 = Pinc.4 , Db5 = Pinc.5 , Db6 = Pinc.6 , Db7 = Pinc.7 _ , E = Pinc.3 , Rs = Pinc.2
Config Lcd = 16 * 2

and the connections are this way :
pins :
1,3,5 -> ground
2 -> VCC
6 -> Pinc.3
etc ...

**Nigel Goodwin** · 31st May 2006, 11:38 PM

Sorry?, I fail to see your point?.

Does that work?, if not why should you think it's correct?, and is your hardware correct?.

akg · 1st June 2006, 06:49 AM

..in ur postes we don't see any lcd initialisation code ..... or is that there is nothing like it?

mhkhosravi · 3rd June 2006, 02:06 PM

It worked
I only changed the port C to port B. it worked

akg · 5th June 2006, 07:09 AM

Quote:

Originally Posted by mhkhosravi

It worked
I only changed the port C to port B. it worked

that's good.. but what was the problem with port C , is it multiplexed with some other function which u haven't disabled.?

mhkhosravi · 5th June 2006, 06:23 PM

The micro had no other functions.only handling LCD.It doesnt work with portC. I dont know why ?
I didnt used any capacitor or resistor. I connected all grounds and VCCs and... directly. maybe it should be used some... It is a strange problem

**Nigel Goodwin** · 5th June 2006, 10:17 PM

Quote:

Originally Posted by mhkhosravi

The micro had no other functions.only handling LCD.It doesnt work with portC. I dont know why ?
I didnt used any capacitor or resistor. I connected all grounds and VCCs and... directly. maybe it should be used some... It is a strange problem

That's why you need to learn assembler!, because it gives you knowledge of the hardware - C insulates you from the hardware (some what!), so you don't know what's going on.

A reasonable knowledge of assembler would probably have enabled you to sort this in the first place?.

madhumita · 9th March 2007, 07:28 AM

we've used the atmel 89c51 controller..n the same lcd.the only output is the black bolcks with the back lights..we've used the assebly language prog..
the program, the connections work well in the protieus.. the testibg software.... but the result is hard to see on the LCD...

we are unabe to trace the problem since a month ...require HELP!!!!

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

30th May 2006, 03:03 PM	(permalink)
mhkhosravi	Problem with JHD 162A LCD Hello I have made a simple circuit with Atmega16 that writes only a word on LCD. when I connect all parts, the LCD only shows full boxes in the second line and the first line is empty. the LCD shows this even when the micro is off !!! The program is correct. the connections is correct too. I used another LCD and micro but they did the same. I dont know where is the problem?! please help me about this ....

30th May 2006, 03:24 PM	(permalink)
Nigel Goodwin	If the contrast is turned up too high, and the LCD isn't initialised at all, then you get the single line of blocks on the display - this is normal, and shows the LCD is worked to some extent at least. As it doesn't work how do you know the program and connections are correct?, one (or both) of then are obviously NOT OK. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

30th May 2006, 03:39 PM	(permalink)
mhkhosravi	because the program is simple, in BASCOM I wrote : $regfile = "M16def.dat" $crystal = 8000000 Config Lcdpin = Pin , Db4 = Pinc.4 , Db5 = Pinc.5 , Db6 = Pinc.6 , Db7 = Pinc.7 _ , E = Pinc.3 , Rs = Pinc.2 Config Lcd = 16 * 2 Lcd "HELLO" and the connections are this way : pins : 1,3,5 -> ground 2 -> VCC 6 -> Pinc.3 etc ... I saw this configuration in some mannuals, but it does not work. If the problem was about the contrast, then only 5 characters must be filled , or all 32 charsets, but only 16 characters of second line become black boxes

30th May 2006, 04:48 PM	(permalink)
mhkhosravi	ok! it may be from program or connections. but which and where?

31st May 2006, 06:02 PM	(permalink)
mhkhosravi	this is for LCD configuration (in BASIC language, with BASCOM ) : Config Lcdpin = Pin , Db4 = Pinc.4 , Db5 = Pinc.5 , Db6 = Pinc.6 , Db7 = Pinc.7 _ , E = Pinc.3 , Rs = Pinc.2 Config Lcd = 16 * 2 and the connections are this way : pins : 1,3,5 -> ground 2 -> VCC 6 -> Pinc.3 etc ...

31st May 2006, 11:38 PM	(permalink)
Nigel Goodwin	Sorry?, I fail to see your point?. Does that work?, if not why should you think it's correct?, and is your hardware correct?. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

1st June 2006, 06:49 AM	(permalink)
akg	..in ur postes we don't see any lcd initialisation code ..... or is that there is nothing like it? __________________ Gods own Country Incredible !ndia www.flickr.com/photos/_akg/ "Give a man a fish, and he will eat for a day. Teach that man to fish, and he will eat for a lifetime."

3rd June 2006, 02:06 PM	(permalink)
mhkhosravi	It worked I only changed the port C to port B. it worked

5th June 2006, 06:23 PM	(permalink)
mhkhosravi	The micro had no other functions.only handling LCD.It doesnt work with portC. I dont know why ? I didnt used any capacitor or resistor. I connected all grounds and VCCs and... directly. maybe it should be used some... It is a strange problem

9th March 2007, 07:28 AM	(permalink)
madhumita	having the same problem we've used the atmel 89c51 controller..n the same lcd.the only output is the black bolcks with the back lights..we've used the assebly language prog.. the program, the connections work well in the protieus.. the testibg software.... but the result is hard to see on the LCD... we are unabe to trace the problem since a month ...require HELP!!!!